Yes, it can be legal to make a silencer. For everything Form-1, from silencer designs that are easily made, to filing forms with the BATF, to 3D modeling. Remember, you must have an approved BATF Form-1 to make a silencer. All NFA laws apply.

Dr.K wrote:Say I or someone in my situation did decide to try different bases on projectiles or ANY RADICAL DESIGN Feature.....

How in blue blazes would I know if it worked or not? I have no testing equipment, (except) my own god given equipment.

Highspeed photography would be a good tool... I used a water filled transparent tube w different colored glitter b/t the 1st 4 baffles. Rented a high framerate digital camera and observed how the glitter traveled when 150psi airhose injected a dynamic impulse...But for bullet base profiles, stagnant open air is needed. Like inside a shop, shooting through an open window. The smoke gas plume will be highly visible and not be disturbed by wind.

What about the Italian compensator bullet?

I think I just saw the problem. My grammer was misleading. I corrected it in the above quotes for clarification.

Perhaps Gunny thought that I meant that a stagnant, open air base was needed. I actually meant that for a test environment. Not a hollow base bullet.

I still think that if any "experimental base" showed promise, it would be the compound S-curve.
But would really like Shockbottle to post links to Academic Paper, Patents, etc.

If Pelton, Bull, or any other Inventor has published Theory or Data, then there is no reason to withhold it.

What POSSIBLE client/customer would care or even know if Public Info was posted on a Public Forum? As Shockbottle himself said, "Patents are a way of proving Bonafides." (Paraphrase)

My "Blue Bells" can't take anymore. Either Put-out or Shut-it. No more teasing.
I'm no masochist.

The Darkest Corners of Hell are reserved for those who remain Neutral!-Dante
The Death of One is a Tragedy, a million only a statistic.-Stalin
Well I AM 1/16 Demon on my Father's Side!-Dresden Files

What do you guys think about 3-5 a2 flash hiders in a tube stacked end to end as baffles for a 22lr can. It probably would not meter well but it would be cheap and easy. Some thing about a law about not having extra suppressor parts?

josephdennis wrote:What do you guys think about 3-5 a2 flash hiders in a tube stacked end to end. It probably would not meter well but it would be cheap and easy. Would the law about not having extra suppressor parts still apply?

Yes it still applies, there is no exemption from having extra parts. Choose wisely what parts you repurpose.

I wouldn't think it would do anything for suppression anyways. Now a stack of muzzlebrakes MIGHT actually do something.

josephdennis wrote:What do you guys think about 3-5 a2 flash hiders in a tube stacked end to end as baffles for a 22lr can. It probably would not meter well but it would be cheap and easy. Some thing about a law about not having extra suppressor parts?

What you propose has been done before.
There are simple designs that work well and are cheap and easy.
Why would you spend 200$ to play and not have good toys.

The only reason after 243 years the government now wants to disarm you is they intend to do something you would shoot them for!

Mueller 877 wrote:What about using the suppressor itself as the gas block in a direct impingement AR platform? Or in the case of a gas piston set up, what about venting the gas block into the suppressor?

The tuning of gas pressure through the gas port is very specific. Also to note, the amount of barrel following the gas port is also key to how much pressure is sent through to cycle the weapon and for how long a duration. This is what led to the mid length gas system for 16" 5.56 barrels over the carbine, as it has less barrel and a shorter duration and less abrupt pressure through the gas port and tube.

Having a sealed system for a piston to vent the gas into a suppressor would also lead to problems, as the ambient air outside of the piston and inside the suppressor would be very high, yet not equalizing nor inhibiting the pressure inside the piston from forcing the piston cup rearward to cycle. But I would still advise against it. An asymmetric rear end of a suppressor that slides around the gas block and subsequent piston or gas tube would give one more internal volume for a blast chamber, but would also prohibit a thread-on suppressor.

It is best to keep the suppressor in front of the moving parts and/or pressure operated system. Although mid-barrel integrated and covert suppressed 10/22's have been done, they are not the same operation.

An armed society is a polite society. Manners are good when one may have to back up his acts with his life.
-- Robert A. Heinlein, "Beyond This Horizon", 1942

I have often wondered if an evacuator like device (think big thing in middle of large tank cannon barrels) could help in relieving back pressure increases...... perhaps in the form of a gas block with a expansion chamber secondary to the main gas entry point???? (think regular gas block/gas port, with gas tube having another hole towards muzzle end, into expansion chamber forward of the gas block)

Also wondered about a can build using a water chamber, that slowly adds water to blast chamber and just past blast baffle as it heats. Easily done with some micro ports.

Also thought about having the baffles designed to spin.... like a turbine, to help slow the gasses by turning the energy into rotary kinetic energy. If arranged properly with every baffle rotating the other way from the adjacent ones, would also create tons of turbulence, and slow the hell out of expanding gasses.... only problem is complexity, and how to keep bearings lubed and moving freely and with little to no noise.

Pman5KMO wrote:I have often wondered if an evacuator like device (think big thing in middle of large tank cannon barrels) could help in relieving back pressure increases...... perhaps in the form of a gas block with a expansion chamber secondary to the main gas entry point???? (think regular gas block/gas port, with gas tube having another hole towards muzzle end, into expansion chamber forward of the gas block)

A bore evacuator does not work in that way, as its purpose is different than what you are describing. The passive bore evacuator on a tank is an out of bore chamber connected through a ring of forward facing holes in the bore. When the round passes this ring, it accepts the high pressure gas the same as a gas port, but stores it and due to the overall area of the holes being far smaller than the overall volume of gas stored within the evacuator, it prolongs the forward blow and subsequent flow of gas and air to evacuate the bore of all gas out the muzzle, keeping any of it from entering an enclosed vehicle. Also key to this design is the timing of the automatic breech to open and eject the spent base/cartridge during the peak of the forward flow, or low pressure in the breech end of the bore, to then ensure enough of the ambient internal air fills the bore to prohibit any of the remaining gas from flowing rearward.

An armed society is a polite society. Manners are good when one may have to back up his acts with his life.
-- Robert A. Heinlein, "Beyond This Horizon", 1942

"A silencer and flash suppressor for sabot projectiles, which includes an accumulation chamber
having a projectile entrance surrounding and closed by the gun barrel and a projectile exit which is spaced
from the projectile entrance by a distance less than the projectile length.
The projectile exit is the smallest diameter of an exit cone
which is surrounded by an annular portion of the accumulation chamber,
which portion may include one or more perforated baffles."

"A silencer and flash suppressor for sabot projectiles, which includes an accumulation chamber
having a projectile entrance surrounding and closed by the gun barrel and a projectile exit which is spaced
from the projectile entrance by a distance less than the projectile length.
The projectile exit is the smallest diameter of an exit cone
which is surrounded by an annular portion of the accumulation chamber,
which portion may include one or more perforated baffles."

"A silencer and flash suppressor for sabot projectiles, which includes an accumulation chamber
having a projectile entrance surrounding and closed by the gun barrel and a projectile exit which is spaced
from the projectile entrance by a distance less than the projectile length.
The projectile exit is the smallest diameter of an exit cone
which is surrounded by an annular portion of the accumulation chamber,
which portion may include one or more perforated baffles."

Also thought about having the baffles designed to spin.... like a turbine, to help slow the gasses by turning the energy into rotary kinetic energy. If arranged properly with every baffle rotating the other way from the adjacent ones, would also create tons of turbulence, and slow the hell out of expanding gasses.... only problem is complexity, and how to keep bearings lubed and moving freely and with little to no noise.

Good ideas. I've drawn a design w/ a standard suppressor down the middle; then "sidelobes" along the length fore and aft of the muzzle.
Looks like a letter H with expansion valves at all 5 lines, w/ I down the middle as a standard suppressor tube.
The 2 rear legs serve the traditional "reflex" pressure sump, though only to the sides of barrel rather than above and below.
The 2 front legs serve to expand and cool gas before venting to atmosphere through trapezoidal slits.
The horizontal leg serves as a blast chamber/muzzle brake.
And the "I" is just a regular (6) 60* cone baffle design.

I've also thought of the rotating spinners design. It turns out that the Germans tried this and the tolerances necessary made the design unsuitable compared to others.
It would probably also sound like a factory assembly line no matter how little bearing surface and slow rotating speeds were used. Though w high speeds for auto use, the freqs might be above human hearing ranges. ???

Instead of turbines, I turned (pun inserted) to stators. Please read my Turbine Blades thread and feel free to add any comments which you may have. Others stated that it was impractical. Perhaps you have some new thoughts on remedying that?
----------------
Historian, I've have to review your posts and then some new patents I've found.
I still think that your foam metal tubing idea has great merit. Spreading the gas release throughout the tube surface via weep holes would solve many problems that a central bore can't overcome.

Best to all of you until I get more time to browse.

The Darkest Corners of Hell are reserved for those who remain Neutral!-Dante
The Death of One is a Tragedy, a million only a statistic.-Stalin
Well I AM 1/16 Demon on my Father's Side!-Dresden Files

In the spirit of throwing out new ideas, which will likely be shot down...

I can't find the reference right now, but somebody in this thread gave me the idea of swirling the gases. In addition to the cone baffles, why not add logitudinal fins arranged so they cause the gases to spin? If the gases could be spun fast enough, they would tend to come into contact with the cones more easily because of centrifugal force. More interaction, lower resulting SPL.

whiterussian1974 wrote: The goal is to smooth the sound, rather than eliminate it. The meter may not show results. But Subjective observation should. ???

Your note on subjective observation is noted and appreciated.
In my experience, this kind of thing happens where what you're measuring isn't what you're looking for. The devices we use to test sound pressure levels frequently measure absolute SPLs. [Un]fortunately, that's not how people perceive sound. We need to specify how SPLs at different frequencies will be weighted. (If my can gives me 140dB at 30kHz and above, the only ones I'll be bothering are the bats.) Our commonly used standards usually don't recognize this. We need better thought-out standards, along with easily affordable equipment to implement them.

fester225 wrote:In the spirit of throwing out new ideas, which will likely be shot down...

I can't find the reference right now, but somebody in this thread gave me the idea of swirling the gases. In addition to the cone baffles, why not add logitudinal fins arranged so they cause the gases to spin? If the gases could be spun fast enough, they would tend to come into contact with the cones more easily because of centrifugal force. More interaction, lower resulting SPL.